---
id: KB-IU-007
url: https://app.codecontract.io/help/manufacturing/metalwork-and-contract-machining
idioma: en
categoria: sector-industria
subcategoria: metalurgia
audiencia: usuario
nivel: intermedio
actualizado: 2026-08-13
tambienEn: [es]
relacionados: [KB-IU-006, KB-IC-012]
citadoPor: [KB-CN-010, KB-IU-017]
---

# Metalwork and contract machining

_Many small orders, drawings that change, and customers asking for certificates months later._

**Responde a:** drawing revision control in a workshop · material certificates for customers · machining traceability · orders with different drawing revisions

A machining or fabrication shop lives on many small orders. The documentary problem is not volume: it is that each order carries a drawing at a specific revision, a material with its certificate and sometimes an outsourced treatment, and all of it disappears as soon as the part ships.

## The three failures that cost money

| Failure | How it happens | Consequence |
| --- | --- | --- |
| Making to the previous revision | The customer emails a new revision | The whole run to be redone |
| Being unable to provide the certificate | It is asked for six months later | Payment withheld or the customer lost |
| Losing the outsourced treatment record | A third party does it and their paper stays there | The assembly ends up unevidenced |

> [!IMPORTANT]
> The first is the costliest and the most avoidable. If the current drawing lives in the order's file rather than in the inbox of whoever received it, nobody can make to a superseded revision without it being visible.

## How to organise it

1. **The order is the file** — Drawing with its revision, material, treatments and inspections, all inside.
2. **Each new revision visibly supersedes the last** — The old one is not deleted: it is marked. It tells you what was made and to what.
3. **The certificate arrives with the material** — That day. Hunting for it six months later is why it never turns up.
4. **And outsourced treatment returns with its document** — If only the part comes back, the set is incomplete and nobody notices until it is requested.

> [!WARNING]
> The blind spot is the sales inbox. Drawings and revisions usually land there, and if that person is on holiday the shop works from whatever was last passed on. It is the origin of failure number one.

## What demanding customers ask for

**En corto**

- The material certificate for that part, not for the supplier in general.
- The drawing and revision it was made to.
- The inspections carried out and their results.
- And sometimes the welder's qualification, with its validity.

When that is answered in minutes, you become the easy supplier. When it takes a week, you are the supplier who has to be chased — and that weighs in the next award.

> [!NOTE]
> The same approach suits fabrication, structural steel, laser cutting and processing generally: the unit is the order, and traceability runs from material to delivered part.

**What if the customer never asks for certificates?**

Keep them anyway: they ask exactly when there is a problem.

**Is it needed for one-off parts?**

The drawing always. The rest, depending on customer and material.

**How do we avoid making to an old revision?**

Have the shop look at the file, not a forwarded email or an undated printout.

## Ejemplos

**A shop makes a run to the previous revision of a drawing received by email.**

- Moves to keeping the current drawing in the order's file
- Marks earlier revisions instead of deleting them

→ The shop looks in one place only and can prove which revision each run was made to.

**The drawing comes from the client and there are several versions.**

- Records which version each batch was made to

→ You know what was made to which drawing.

**The client supplies the material and it is not recorded.**

- Records intakes and consumption per client

→ You answer when they ask.

**A client asks for a part's material certificate.**

- Ties the part to the consignment received

→ The certificate is located without searching.

**The drawing changes midway through a run.**

- Records from which unit it applies

→ You can say what each one carried.

**Material is left over and there is a dispute over whose it is.**

- Agrees in writing what happens to leftovers

→ The conversation is settled by the agreement.